This invention relates to the use of iron oxide magnetic tape as high resistance electrical conductors in electromagnetic radiation, and to improved electric and magnetic probes made possible by such leads.
Until about ten years ago, fine twisted pairs of nichrome or Evanohm (Ni-Cr-Al) wire were the leads for electric and magnetic probes of microwave fields, and these were replaced by carbon impregnated Teflon.RTM. leads developed at the U.S. Bureau of Standards at Boulder, Colo.
Prior art diode-detector probes used in free space measurements were not uniquely electric or magnetic. In electric probes, the connections of the twisted leads to the two sides of the detector formed a small magnetic loop probe superimposed on the electric probe. Precaution was taken to orient the plane of the loop parallel to the magnetic field; that precaution was difficult to accomplish in measurements near objects. Previous attempts to employ square loop diode-detector magnetic probes in free space have failed. Even for the two orientations 180.degree. apart in which the side containing the diode was perpendicular to the electric field, the electrometer readings differed by as much as 10 percent.